The present invention relates to a process for manufacturing a perfected plastic buckle for belts and similar and a buckle produced using such a process. In particular, the buckle covered by the present invention comprises a frame structure in which slides at least one crossbar.
Buckles for belts or similar are already known whereby the strip material (belt, strap or similar) held in place by the buckle itself may be tightened or loosened by the user employing one hand. Such buckles usually comprise a four-sided frame with a crossbar sliding inside the same so as to define inside the same two adjustable apertures separated by the crossbar itself. One of the cross members on the frame, parallel with the sliding bar, is designed for permanent connection of a first end of the strip material to be held in place, whereas a portion of the second end of the said strip material may be held in place by the buckle, in releasable manner, by inserting it from underneath into the first of the said apertures adjacent to the said cross member on the frame, by passing it over the said sliding crossbar and out through the second said aperture where it is held tight between a second cross member on the frame, parallel with the first, and a main portion of the said second end of strip material, after being tightened flat with the buckle. Buckles of the aforementioned type are usually made of metal in two pieces bent and connected to each other, or of plastic comprising a first part fitted firmly with the said sliding crossbar and housed in guillotine manner in a seat formed inside the frame which is therefore hollow. Withdrawal of the guillotine part from the frame is prevented, after insertion, by securing on the latter the said first end of strip material to be held in place. Buckles of the aforementioned type involve a number of drawbacks. In particular, the metal types are subject to corrosion and rust rapidly during use, whereas the plastic types, in addition to being relatively large in size, involve high production cost, owing to their being formed in two parts produced separately and later fitted one inside the other. Furthermore, prior to securing the strip material, no means is provided for securing the part sliding inside the hollow frame, which may thus come out and be lost.